Geological Society of London. 
177 
and 0-77 per cent. of silica. The altered rocks contain an abund- 
ance of quartz granules, due probably to the crystallization of pro- 
gressively dissociated silica, as the specimens of rock in wbicb these 
gratiules occur do not contain a larger proportion of silica tban tbose 
in wbicb its presence can hardly be detected under the microscope. 
The proportion of alkalies in the different specimens does not 
materially vary. 
Overlying the second qnarry at the east end of the mountain is an 
asb bed of reddisb-brown colour, containing rnore tban 10 per cent. 
of protoxide of manganese and uearly 20 per cent. of peroxide of 
iron, and showing a great diminution in the per-centage of silica 
wben compared with the associated crystalline rock. 
The author further described the cbaracters of the uralite-por- 
pbyry of the Mawddach valley near Dolgelly, whicb is of a greyish- 
green colour, spotted with black, and consists of a granulär base 
inclosing patcbes and crystals of uralite, the outlines of wbicb are 
sometimes sbarp and well defined, but generally rounded and inerging 
into the general base. 
2. “ On new species of Belemnites and Salenia from the Middle 
Tertiaries of South Australia.” By Balpb Tate, Esq., F.G.S., Pro- 
fessor of Natural Science in the University of Adelaide. 
The author noticed the occurrence in deposits of supposed Miocene 
agein South Australia of a species of Belemnite ( Belemnites senescens ) 
and a Salenia (S. tertiana). These fossils were obtained from 
Aldenga, twenty-six miles south of Adelaide, on the east coast of St. 
Yincent’s Gulf, where the long series of sea-cliffs contains an assem- 
blage of fossils identical with that of the Murray Biver beds. The 
Salenia is especially interesting on account of the discovery of a 
living species of the genus by the naturalists of the ‘ Challenger.’ 
3. “ On Mauisaurus Gardneri, Seeley, an Elasmosaurian from the 
base of the Gault at Folkestone.” By Harry Govier Seeley, Esq., 
F.L.S., F.G.S., Professor of Geography at King’s College, London. 
The author described the skeleton of a great long-necked Saurian 
obtained by Mr. J. S. Gardner from the Gault of the cliff at Folke- 
stone. The remains obtained included a tooth, a long series of 
vertebrae, some ribs, bones of the pectoral arch, the femur, and some 
phalanges, indicating a very large species, which the author referred, 
with some doubt, to the genus Mauisaurus of Dr. Hector, founded 
upon a Saurian from the Cretace.ms formation of New Zealand. He 
gave it the name of Mauisaurus Gardneri, in honour of its discoverer. 
A small heap of pebbles was found in the neighbourhood of the ribs, 
and it was supposed that these had been contained in the stomach of 
the animal. 1 
1 Mr. J. W. Hulke, with regard to the pebbles, suggested that the animal may not 
have swallowed them as an aid to the comminution of food in its stomach, but that 
they were introduced in the stomachs of fish which it had swallowed. The flesh and, 
subsequently, the bones of these would be digested and absorbed, whilst the indiges- 
tible stones, ii the stomach of the Ptesiosaurm was like that of Crocodiles, would be 
unable to pass through the small pyloric opening into the intestine, and must perma- 
nently remain in the stomach. 
DECADE n. V0L. IT. — XO. IV. 
12 
